High-temperature corrosion behavior of sputtered K38 nanocrystalline coatings with and without yttrium addition in molten sulfate at 900 °C

► Synergistic effect of nanocrystallization and reactive element on corrosion behavior. ► Nanocrystallization increased corrosion resistance in molten sulfate. ► Addition of yttrium further promoted the rapid formation of protective scale.